The human heart is the muscle that is responsible for pumping blood throughout the vascular network. Veins are vessels that carry blood toward the heart while arteries are vessels that carry blood away from the heart. The human heart consists of two atrial chambers and two ventricular chambers. Atrial chambers receive blood from the body and the ventricular chambers, which include larger muscular walls, pump the blood from the heart. A septum separates the left and the right sides of the heart. Blood from the veins of the vascular network enters the right atrium from the superior and inferior vena cava and moves into the right ventricle. From the right ventricle, the blood is pumped to the lungs via pulmonary arteries to become oxygenated. Once the blood has been oxygenated, the blood returns via pulmonary veins to the heart by entering the left atrium. From the left atrium, the blood enters the left ventricle and is pumped into the aorta and then into the arteries of the vascular network.
For the vast majority of the population, the events associated with the movement of blood happen without circumstance. However, for many people the heart fails to provide adequate pumping capabilities. These heart failures may include congestive heart failure (commonly referred to as heart disease), which is a condition that results in any structural or functional cardiac disorder. The structural or functional disorder impairs the ability of the heart to fill with or pump blood throughout the body. Presently, there is no known cure for heart disease and long-term treatment is limited to a heart transplant. With only a little over 2,000 patients receiving a heart transplant each year, and over 16,600 more on the waiting list for a heart, there is a persisting need for a cure or at the minimum a means of improving the quality of life of those patients on the waiting list.
One such means of bridging the time gap while awaiting a transplant is a circulatory assist system. Circulatory assist devices were developed over a decade ago and provide assistance to a diseased heart by way of a mechanical pump. In this way, the circulation of blood through the vascular network is aided despite the presence of diseased tissue. Traditionally, these circulatory assist devices include an implantable pump, a controller (internal or external), and inflow and outflow tubes connecting the pump to the vascular network. FDA approved circulatory assist devices may be used to partially relieve symptoms of breathlessness and fatigue associated with severe heart failure and can drastically improve a patient's quality of life.
However, the conventional surgical process associated with the circulatory assist system is highly invasive. At the very least the procedure involves a thoracotomy, i.e., the opening of the thoracic cavity between successive ribs to expose the internal organs. More typical is cardiac surgery, generally known as open-heart surgery, where the sternum is cut and split to expose the internal organs. Once the thoracic cavity is accessed, the physician must enter the pleural space and puncture both the pericardium and the myocardial wall. There are great risks and an extensive recovery time associated with the invasive nature of the implantation surgery. As such, some patients with severe symptoms are not healthy enough for surgery to receive a circulatory assist system.
The transseptal cannula, described in related U.S. patent application Ser. No. 12/256,911, the disclosure of which is incorporated herein by reference, provides greater accessibility to the circulatory assist device to those patients that would receive the most benefit by minimizing the invasiveness of the implantation surgery. Yet, there continues to be a need to implement additional features that would further facilitate the delivery of the transseptal cannula and/or that would allow the physician to maintain greater control over the transseptal cannula device during the surgical procedure.